Device for pulling rock-drills when stuck



G. DAVIDSON.

DEVICE FOR PULLING ROCK DRILLS WHEN STUCK.

APPLICATION FILED AUG.9, 1919.

Patentd May 4,1920.

//VVE{V 70/? Gearye Da /030 GEORGE DAVIDSON, 0F BRITANNIA BEACH, BRITISH COLUMBIA, CANADA.

DEVICE FOR PULLING ROCK-DRILLS WHEN STUCK.

Specification of Letters Patent.

Patented May 4, 1920.

Application filed August 9, 1919. Serial No. 316,358.

To all whom it may concern:

Be it known that I, GEORGE DAvmsoN, a subject of the King of Great Britain and a resident of Britannia Beach, in the rovince of British Columbia, Canada, have invented certain new and useful Improvements in Devices for Pulling Rock-Drills WVhen Stuck, of which the following is a specification.

My invention relates to improvements in devices for pulling rock drills when stuck, and the object of my invention is to provide a simple and practical means whereby such drills may be drawn out of a hole when stuck therein during the drilling process in a much quicker and more convenient manner than is possible under the present practice.

I attain this object by the construction illustrated in the accompanying drawings in which- Figure 1 is a side elevation of my devh.

Fig. 2 is a plan View.

Similar figures of reference indicate similar parts throughout the views.

1 indicates an exteriorly threaded cylinder having a smooth bore adapted to slidably fit the drill 2, the lower end of the cylinder being plain, as at 3, and provided with spikes or feet 4-. 5 indicates a sleeve consisting of connected upper and lower boxes 6 and 7, the lower one of which is threaded internally correspondingly t0 the threaded cylinder 1. while the upper box 6 is adapted to lit the drill and is provided with three projections 8 which fit three corresponding grooves 9 in the drill body, which has normally four grooves, a groove 10 being formed in the box 6 designed to register with the fourth drill groove when the projections 9 are in engagement with the other drill grooves. Both boxes 6 and 7 are squared on their outer sides so that a handle 11 may be placed on either of them, as desired.

The manner in which the device is used may be briefly described as follows. Ordinarily when a drill becomes stuck in a hole during the drilling operation it is a difficult matter to draw it out but with the device just described it may be pulled with great facility and ease. To effect this the assembled device is placed over the drill and slid along the same to the face of the rock, as shown in Fig. l, and a key 12 is inserted into the unoccupied groove of the drill and the groove 10, thus firmly uniting the sleeve and the drill. The handle 11 is then placed on the box 6 or 7 as desired, and the sleeve rotated in the direction necessary to unthread the box 7 off the cylinder, thus causing the box to rise thereon and consequently raising box 6 and therefore the drill 2, the turning operation being continued until the drill is free.

From the foregoing it will be seen that I have devised a simple means whereby rock drills may be readily pulled from holes in which they have become stuck during drilling operations.

What I claim as my invention is A device for pulling grooved rock drills when stuck, comprising an externally threaded cylinder provided with anchoring GEORGE DAVIDSON. 

